In the welding industry, tremendous numbers of robotic welding stations are operable to draw welding wire from a package as a continuous supply of wire to perform successive welding operations. The advent of this mass use of electric welding wire has caused tremendous research and development in improving the packaging for the bulk welding wire. A common package is a drum where looped welding wire is deposited in the drum as a wire stack, or body, of wire having a top surface with an outer cylindrical surface against the drum and an inner cylindrical surface defining a central bore. The central bore is often occupied by a cardboard cylindrical core as shown in Cooper U.S. Pat. No. 5,819,934. It is common practice for the drum to have an upper retainer ring that is used in transportation to stabilize the body of welding wire as it settles. This ring, as is shown in Cooper U.S. Pat. No. 5,819,934, remains on the top of the welding wire to push downward by its weight so the wire can be pulled from the body of wire between the core and the ring. Each loop of wire has one turn of built-in twist so that when it is paid out, the twist introduced by releasing a loop of wire is canceled. Hence the wire is “twist-free” when it reaches the contact tip of the welding gun. The built-in twist causes the wire to spring up from the top of the stack when unrestrained. The weighted ring prevents wire from springing up due to the built-in twist. The weight of the ring is critical. Heavier rings tend to bend or recast the wire, causing wire to wobble when it exits the contact tip, although it is more effective to prevent tangle. Lighter rings can be easily lifted by the wire during payout, thus losing its contact to the top of the wire stack; and thereby losing its intended purpose of restraining wire movement at the top of the wire stack. Lighter rings have more propensity of tangle, although producing less wire wobble. This is the pitfall of the weighted ring design, essentially facing the difficulty of striking a balance of less tangle and less wire wobble. Tangles are detrimental to the operation of the package since they cause down time of the robotic welding station. Tangles are caused by many adverse movements of the wire loops on top of the wire stack. The wire has a winding cast that can snap around the outside of the retainer ring or the wire can bunch and slip at the inside of the retainer ring. The most common tangle is caused as wire is pulled from the inside of the ring and is referred to as “e script” because of its shape. An e script tangle stops operation of the welder and must be removed. Retainer rings so far on the market are not effective in preventing e script tangles. This type of tangle is caused by poor alignment of drive rolls of the wire feeder that builds up back-twist in the wire as it feeds the wire. The twist ultimately makes it way back to the drum and leads to an e script tangle. The objective of a retainer ring design is to increase operating welding time between successive e-tangles. The weighted retainer rings have not been successful in eliminating such tangles. The present invention is related to a retainer ring which essentially eliminates e script tangles in the welding wire being pulled from the center of the looped wire body of a drum package.
In addition, due to the high volumes of wire used during many welding operations, especially robotic welding operations, there is also a need for a wire package that can be easily and economically disposable. As can be appreciated, it is not economical to re-use the packaging utilized to ship and dispense the welding wire.